This study will use linked workers'compensation and Social Security Administration data to determine the impact of workplace injuries and illnesses on long-term earnings, income replacement from workers'compensation and federal disability insurance programs, withdrawal from the labor force, and the use of Social Security Disability Insurance (SSDI) and supplemental Security Income (SSI) benefits. We will also estimate how lost earnings, receipt of benefits, withdrawal from the labor market, and propensity to use SSDI/SSI benefits are affected by age, sex, body part, type of injury, and industry. The study will use data on all cases receiving workers'compensation income benefits in 5 states: California, New Mexico, Oregon, Washington, and Wisconsin. This study will improve our understanding of the economic impacts of occupational injuries and illnesses. It will provide better estimates of lost earnings than previously available and will provide them for a period stretching up to 14 years after the date of injury. It will also provide improved estimates of the degree to which losses are replaced, by providing information not only on workers'compensation benefits but also on the receipt of SSDI and SSI benefits. It will improve our understanding of the differential effects of injuries on the incomes of older compared to younger workers and of women compared to men. We will also estimate the economic impact of workplace injuries and illnesses by industry, by firm size, by part of body, and by nature of injury. We will use the industry categories designated by the National Occupational Research Agenda. These aspects of occupational injuries and illnesses are important of themselves, but they can also help in decisions about targeting prevention and research activities. Information about the receipt of SSDI and SSI benefits will also provide a measure of the population with the most disabling workplace injuries and illnesses, because these programs target workers expected to be unable to work for long periods.